enhance robot unit test to verify behavior of resolve_dependencies with force/retain_all_deps enabled
add retain_all_deps key in build options, only set to True when building dep graph
avoid side-effects on 'unprocessed' argument in resolve_dependencies, make it listen to retain_all_deps build option instead of force
add debug info
fix side-effects of find_resolved_modules, stop trying to deepcopy 'unprocessed' in resolve_dependencies (doesn't work in Python 2.4)
Merge pull request #828 from boegel/fix_forced_robot

fix combining --force and --robot